public class _1search {
    //二分查找
    public int search(int[] nums, int target) {

        int left = 0,right = nums.length-1;
        while(right >= left){
            int mid = left + (right - left)/2;
            if(nums[mid] > target){
                right = mid-1;
            } else if (nums[mid] < target){
                left = mid+1;
            } else {
                return mid;
            }
        }
        return -1;
    }
}
